Jump to content

Sharp X68000 SUPER Capacitor Replacement Guide

From RetroTechCollection
Sharp X68000 XVI power supply schematic (service manual)
Sharp's circuit diagram of the SH4 power supply from the X68000 XVI service manual; the SUPER uses the same board

The Sharp X68000 SUPER (CZ-604C) and SUPER-HD (CZ-623C) use the SH4 power supply, the same board as the Sharp X68000 XVI, EXPERT, EXPERT II and Sharp X68030.[1][2] Sharp's circuit diagrams for that supply and for the XVI's boards are in the Sharp X68000 XVI Service Manual, and the full procedure for removing, recapping and testing the SH4 is on the Sharp X68000 XVI Capacitor Replacement Guide. The lists below are Poe's, from a SUPER he restored after it stopped powering on, compared here with Sharp's XVI diagrams.[2]

Warning: the supply runs from 100 V mains, and the primary side keeps more than 100 V DC on C9 after the plug is pulled. Unplug the machine and measure across C9 before touching the primary side.[3]

Power supply (SH4)

[edit | edit source]
SH4 power supply electrolytics (Poe's SUPER list)
Ref Value Voltage Original series Poe's replacement
C9 470 µF 180 V ELNA 470 µF 250 V
C24 1000 µF 25 V ELNA RSG 1000 µF 25 V
C25 680 µF 16 V ELNA RSG 680 µF 16 V
C27 220 µF 25 V ELNA RSG 220 µF 25 V
C28 100 µF 16 V ELNA RJ3 100 µF 16 V
C31 100 µF 10 V ELNA RJ3 100 µF 10 V
C33 220 µF 16 V ELNA RSG 220 µF 16 V
C34 100 µF 6.3 V ELNA RJ3 100 µF 10 V
C35 10 µF 25 V ELNA RJ3 10 µF 50 V
C38 3.3 µF 50 V ELNA RJ3 3.3 µF 50 V
C40 5600 µF 10 V ELNA RSG 5600 µF 10 V
C41 5600 µF 10 V ELNA RSG 5600 µF 10 V
C42 2200 µF 6.3 V ELNA RJ3 2200 µF 10 V

[2] These 13 values and voltages are the same as those on Sharp's diagram of the SH4 in the XVI service manual.[4] In Poe's SUPER, C24, C27, C40, C41 and C42 had leaked heavily.[2] Fit C27, C28 and C31 by the silkscreen on the board: Fram found that Sharp's diagram draws all three with the wrong polarity.[5]

Main board (6792DE)

[edit | edit source]
SUPER main board electrolytics (Poe)
Ref Value Voltage Notes
C22 470 µF 10 V Poe fitted a 16 V part
C23 2200 µF 6.3 V Poe fitted a 16 V part
C32 0.47 µF 50 V Low-profile
C35 220 µF 6.3 V Low-profile, yellow; Poe fitted a 10 V part

[2] The XVI's main board, a different design (K7243DE), has four electrolytics of the same four values under other reference numbers.[6]

Control board (base)

[edit | edit source]
SUPER control board electrolytics (Poe)
Value Voltage References
100 µF 16 V C209, C211, C227, C235, C242, C259
100 µF 10 V C234, C243, C261
100 µF 6.3 V C210, C212, C224, C237, C238, C249
47 µF 16 V C208, C252, C253
22 µF 16 V C217
10 µF 16 V C225
4.7 µF 50 V C201, C202, C203, C204, C207, C226, C230, C260
1 µF 50 V C218, C233, C258
0.47 µF 50 V C231, C232, C236, C247, C264

[2] That is 36 electrolytics. Poe marks C203, C211, C217, C218, C230, C235, C236, C242 and C243 as low-profile parts.[2] The references, values and voltages match the XVI control board on Sharp's diagram, so the positions given in the XVI guide are a useful map.[6] Poe's board number for the SUPER's base board is K6793DE.[2]

Analogue board (K6794DE)

[edit | edit source]
SUPER analogue board electrolytics (Poe)
Ref Value Voltage Notes
C403, C404, C405 470 µF 10 V VX(M) 85 °C; Poe fitted 16 V, 105 °C parts
C407, C408, C410 100 µF 16 V VX(M) 85 °C
C406, C411 100 µF 6.3 V VX(M) 85 °C; Poe fitted 16 V parts

[2] The same eight values appear on the XVI's analogue board, where C403 to C405 sit in series with the red, green and blue outputs.[6]

Expansion slot board (K6795DE)

[edit | edit source]

Poe lists C801 to C804 as 47 µF 10 V low-profile parts and replaced them with 47 µF 16 V.[2] On Sharp's XVI diagram C803 and C804 sit on the +12 V and −12 V lines and are rated 16 V, while C801 and C802 on the +5 V lines are 10 V.[6] Read the cans on your board, and fit 16 V parts at C803 and C804.

Memory board

[edit | edit source]

The memory expansion board in Poe's machine has two electrolytics, C2 and C3, both 100 µF 10 V low-profile.[2]

Floppy drives

[edit | edit source]

Poe's list for the drives in this SUPER has C17 and C19 (100 µF 16 V, Nichicon N728 low-profile), C10, C21, C23 and C26 (10 µF 16 V, 4 × 5 mm), and, as an alternative set marked "or", C16 (10 µF 16 V), C17 (100 µF 16 V) and C18 to C21 (47 µF 25 V). Unnumbered parts are two 22 µF 16 V (5 × 5 mm), one 10 µF 16 V (4 × 5 mm) and one 1 µF 50 V bipolar (4 × 5 mm), for which he fits a 5 × 11 mm part lying on its side.[2] Because the list gives two alternative sets, read the drive board before ordering. Poe warns against removing the spindle or stepping motor just to reach the capacitors.[7] See Floppy Drive Repair.

Replacement procedure

[edit | edit source]

The supply is removed, recapped and tested in the same way as the XVI's; follow the procedure on the XVI capacitor guide. Points that Poe adds from the SUPER:

  1. Before removing the capacitors he soaked the supply board in isopropyl alcohol for about five minutes, deep enough to cover the component legs, to loosen the electrolyte and dirt.[2]
  2. After removing them he cleaned the leaked electrolyte off both sides of the board with a toothbrush and cotton buds.[2]
  3. He cleaned up and refitted some of the other parts he had taken off.[2]

After the recap

[edit | edit source]

The SH4's output connectors and their voltages are tabled on the XVI capacitor guide.[4] If a rail is missing, go to the Sharp X68000 SUPER Troubleshooting Guide.

[edit | edit source]

References

[edit | edit source]
  1. ↑ X68000シリーズ電源のハンダ面から見た抵抗配置図– Kunihiko Ohnaka (kunichiko), 2020-10-10—link(accessed 2026-10-21) Supply by model, quoted from Poe: SUPER and SUPER-HD (CZ-604C, CZ-623C) use the SH4, as do the EXPERT, EXPERT II, XVI and X68030.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 SHARP X68000 SUPER / SUPER-HD CZ-604C CZ-623C 修理備忘録– Poe—link(accessed 2026-10-21) Repair of a SUPER (no hard disk) that would not power on. Capacitor lists with original series and replacements: memory expansion C2, C3 100 µF 10 V; analogue board C403 to C405 470 µF 10 V, C406 and C411 100 µF 6.3 V, C407, C408, C410 100 µF 16 V (VX(M) 85 °C); expansion slot board C801 to C804 47 µF 10 V low-profile (replaced with 16 V); main board C22 470 µF 10 V, C23 2200 µF 6.3 V, C32 0.47 µF 50 V, C35 220 µF 6.3 V; control board 36 parts C201 to C264; floppy drive list; SH4 supply C9 to C42 with ELNA RSG and RJ3 series and replacement voltages. C24, C27, C40, C41 and C42 had leaked heavily. Board soaked in IPA for about five minutes to the depth of the component legs before the capacitors were removed; both sides cleaned with a toothbrush and cotton buds; some removed parts cleaned and reused. Boards: power supply SH4, main 6792DE, base K6793DE, analogue K6794DE, expansion slot K6795DE, external interface K6796DE, lamp boards K6798DE to K6800DE.
  3. ↑ X68kXVI HDの電源リペア– Fram, 2015-05-23—link(accessed 2026-10-21) The SH4's primary side holds more than 100 V DC after the plug is pulled.
  4. ↑ 4.0 4.1 Sharp, service manual CZ-134 for the X68000 XVI (File:Sharp X68000 XVI Service Manual.pdf), 22, power supply basic wiring diagram, printed pages 97 and 98 (PDF page 85); see Sharp X68000 XVI Service Manual. SH4 board UADP-0069CEZZ with C9 470 µF 180 V, C24 1000 µF 25 V, C25 680 µF 16 V, C27 220 µF 25 V, C28 100 µF 16 V, C31 100 µF 10 V, C33 220 µF 16 V, C34 100 µF 6.3 V, C35 10 µF 25 V, C38 3.3 µF 50 V, C40 and C41 5600 µF 10 V, C42 2200 µF 6.3 V; output connector pin-outs.
  5. ↑ 【訂正】X68kの電源ユニットのシルク印刷に間違いがあった件&X68kの電源修理再び(未完)3– Fram, 2024-03-24—link(accessed 2026-10-21) The service manual diagram of the SH4 draws C31, C27 and C28 with reversed polarity; the board silkscreen is correct.
  6. ↑ 6.0 6.1 6.2 6.3 Sharp, service manual CZ-134 (File:Sharp X68000 XVI Service Manual.pdf): XVI main board K7243DE with C10 0.47 µF 50 V, C16 470 µF 10 V, C17 2200 µF 6.3 V, C24 220 µF 6.3 V (printed pages 75 to 84, PDF pages 73 to 77); control board diagram with 36 electrolytics C201 to C264 of the same values as Poe's SUPER list (printed pages 85 and 86, PDF page 78); expansion slot lines C801 47 µF 10 V (VCC1), C802 47 µF 10 V (VCC2), C803 47 µF 16 V (+12 V), C804 47 µF 16 V (−12 V) (printed pages 89 and 90, PDF page 80); analogue board C403 to C405 470 µF 10 V in the RGB outputs, C406, C411 100 µF 6.3 V, C407, C408, C410 100 µF 16 V (printed pages 93 and 94, PDF page 83).
  7. ↑ SHARP X68000 FDD K61432-71 K61432-72 K-61435-72 修理– Poe, 2020-02-23—link(accessed 2026-10-21) Do not remove the spindle or stepping motor just to change capacitors, because the head position is set against the index timing.


Retrieved from "https://retrotechwiki.com/index.php?title=Sharp_X68000_SUPER_Capacitor_Replacement_Guide&oldid=28985"